About MINUS 90

MINUS 90 was founded by cavers Dan Green and Katie Graham to supply project explorers with exceptional gear. MINUS 90 celebrates Dan’s creative connection to the sport and Katie’s significant contributions to the forefront of exploration.

Inventor Dan Green brings over 25 years of hands-on outdoor equipment design experience, including a tenure as VP of Design at Arc’teryx Equipment. His extensive industry background has sharpened his expertise in product development, focusing on materials, construction, and manufacturing. Committed to enhancing fit and durability, Dan has been evolving his caving coverall designs since 1995. At MINUS 90, Dan leads product design and development.

Cofounder / Field Ambassador Katie Graham quit corporate accounting to immerse herself in North America’s leading caving and canyoning expeditions, including the 1,500-meter-deep Sistema Cheve project in Mexico and the 51-rappel first descent of Waffl Canyon down the west face of Mt. Robson. Katie recently set the Canadian cave depth record by diving to the bottom of Bisaro Anima Cave in the BC Rockies. In 2024, she joined a small, dedicated team to establish the deepest cave in the continental USA. Katie’s role at MINUS 90 is to stay connected to mountain exploration culture and manage finances—in that order.

MINUS 90 History

1991:    Dan discovers caving. For gear repair, he teaches himself to sew.

1995:    Obsessed with getting a better fit, Dan builds his first caving coveralls from denim cut from seven pairs of 501 jeans. The 501 fly buttons run the full length of the front flap.

1998:    Dan’s university bachelor's thesis is titled Ideal Speleological Apparel. He got research help from the late Bill Mixon of Texas, who maintained one of the largest caving libraries in North America. Of the final result, Mixon remarked, 'Dubious, at best.’

2000:    Dan registers MINUS 90 in Alberta and begins making caving coveralls and packs for local Rockies cavers. He is soon recruited by the Arc'teryx design department, bringing only his coveralls and a caver pack to the interview. 

2007:    Schooled in the design and development world of materials, patterns, construction and manufacturing, Dan redesigns the coverall from the ground up and establishes a local reputation for excellent gear. 

2008:    Katie rigs her stop backwards while hanging in Dan's tree. Dan suggests that prominent Rockies project cavers are showing poor judgment by taking rookie caver Katie Graham into difficult caves.

2010:    Katie and team break the Canadian cave depth record that had stood since 1972.

2013:    Dan passes Katie an old sewing machine and caving patterns— she hacks the first women’s coverall pattern. Emphasis on hack.

2018:    Dan gives an experimental silicone-coated fabric to Katie for her latest coveralls. The unexpected, excellent results lead to a breakthrough in caving fabric.

2019:    Katie and team break the Canadian cave depth record for the second time in a decade, this time when Katie dives a sump in the bottom of Bisaro Anima to 683 metres deep.

2022:    Dan and Katie join forces to bring MINUS 90 to life. Dan completes the new coverall pattern before bringing in talented design and pattern engineer Capri Philip to create the women’s pattern and all the sizes. A huge step forward. 

2023:    MINUS 90 develops 700HT with a specialized mill in Sweden, coating a dense high tenacity nylon with a proprietary silicone. 

2024:    Katie and team break the USA/CAN depth record again, pushing Montana’s Tears of the Turtle to a depth of 750 metres.

2024:    MINUS 90 launches the ARGO and Cheve coveralls with 700HT fabric.